Means for producing a vacuum.



P. H. THOMAS.

MEANB FOR PRODUCING A VACUUM.

Amunnlon FILED JAN. 23, 19 04.

91 141 PatantedJanllQlQll.

NIT D sTA Es- PATENT OFFICE.

PERCY H. THOMAS, OF EAST ORANGE, NEW. JERSEY, ASSIGNOR TO ooorER HEWITT ELECTRIC cOMrANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

Means FOR rnonuome A vAoUUM.

Specification of Letters Patent.

Application filed January 23, 1904. Serial No. 190,283.

To all whom it may concern:

lie it known that I. lnuev ll. Tuoams, a citizen of the United States, and residentof liast Orange, county of Essex, State of New Jersey, have invented certain new and useful Improvements. in Means for Producing a Vacuum, of which the following is a I I n t A broader conception of the nvention would contemplate the-invention merely as a means for securing a vacuum for-"what ever purpose, and would not necessarily involve the use of the apparatus fpr a purpose to the accomplishment of which the pres ence of a condensed liquid would contribute.-

As an example, however, ofa particular use to whichthc present invention adapts itself,

for -ca rryin o I may mention the well-knowl'i mercury vapor'electric apparatus, and for conveniencethe present specification will'des'crihe and the drawings will illustrate an apparatusof' this class.

The principle of the invention. resides in utilizing the va or of a volatilizable liquid the gases which iti's desired to exclude from the containin vessel. To this end the vapor, which may e me'rcury'vapor, is caused to be expelled by any suitable means from the vessel, carrying with it all deleterious gases. [When this process has been continued long enoughto purify the chamber of the vessel from all gases which it is desired to remove, -the exitchamhcr is sealed off while the process of ex: pulsion is going on, thus preventing any return of noxious gases into the chambcr. In order to secure the-best results, the seal-- ing ofl should'not take place until the time'- has arrived when. the gases or vapors issuing from the exit chamber consist wholly of the vapor selected as the eareicr tor the noxious gases or of such other gases as may be utilized for the purpose of cleansing or evacuating the chamber. I

My invention will be understood by reference to the accompanying drawing which is an elevation and partseetion of an apparatus adapted to carrying out my invent-1on.- g i Inthe drawing, 1 is the container of :a mercury vapor apparatus such as is adapted for use as a circuit-breaker for controlling elcctric circuits. The said container is sup 'plled withelectrodes, 2 and 3, one of which is the 'POSItIVG and the other the negative Pate11ted-Ja-n.-- 10, 1911.

electrode of the apparatus. These electrodes 'may be'o'f mercury or one of the said electrodes may be of mercury or other suitable conducting fluid and the other mav' be of a solid material, such as iron. Lead-wires, 4 and 5, are connected,respectively, with'th'e electrodes 2 and 3.: When-the device is to he used as 'a'circuit-breaker, the mercury ma be caused to form a normal conducting pat 1 between the electrodesyas illustrated at 6.

This, however, is a detail which may be varied accord ng to -c1rcumstanccs, and 1t should be understood that this particular form of "aporapparatus, is'solected merely for the purposes of illi 1stration. The same mode 'of 1uauufacture may be employed whether the apparatus is to be used as acircuit-breaker, a lamp, a current rectifier,

or for-any other purpose. I

I may place above. the mercury in the container 1 a thin sheet or film. 7, of water .for' a purpose to be explained hereinafter.

This film of water may, however, be omitted, if'preferred. A

The apparatus as shown is provided'with an exit tube, 8, through which vapors or gases may be ex elled before th'e seallng of the apparatus ta es place, -I generally surround the apparatus, during the process of manufacture, with a heat retaining shield, 9,

the function of which may be rea 11y under- ,stood. .Belowtheapparatus I- place one or more flames or torches 10, 10,-for volatilizing the liquid in the container 1, or a por-- tion thereof, and causing the removal of all.

injurious gases or vapors.

5 When the Operation of creating a vacuum within the chamber is ready-to begin, the jets l0, IQ, are ignited and' heat is applied to thecontainer, causing, first, avapor zation of the film of water 7 and theexpulsion of its vapor through the exit tube 8. By these means some of the injurious gases are removed. A portion of the mercury is then volatilized by the continuedapphcatlon of heat, the gases originally contained with. l

in the apparatus disseminating themselves through the vapor thus produced and when out Z the mixed gases and vapors pass through the exit tube 8, all of the iiipirious gases in the container are finally carried ott'.

As already stated this process is continued until the gases passing through the exit tube 8 are practically pure mercury vapor. 1 The tube is then sealed ott at 11. Willi? the i without the use of an external pump which i is itself capable of exhausting the chamber to the required degree.

The same process might be' utilizcd for producing a vacuum for any purpose as already explained.

In employing the, term volatiliz'ahle fluid. in the present specification claims it is intended to include substances 1 which may be acted upon by chemical or any othersuitable means for producing the necessary gas or vapor for clearingthe chamber. q

The narrow throat 11 serves a critical function in connection with the present vention. to wit. that it reduces thecross-secl l second liquid for the purpose of washing 1 1 tion of the passage through which the vapor of mercury or other vapor utilized to expel the deleterious gases incloscd within the chamber pass. By virtue of the narrowing of the cross-section as described. the velo. ray of the gas or vapor utilized for this purpose is greatly increased until it exceeds the velocity of the diffusion of any of the deleterious gases beyond the-narrow throat. hen the exhaustion is complete or carried to a satisitactory limit. the apparatus may be sealed otf at any point on the outside of i throat 11.

discontinued Itis well known that certain chemical processes which can be excited by suitable means produce large. volumes of gases or vapors. Gases or vapors formed by such a chemical process may be utilized in place of the vapor produced from the mercury within the chamber by heat to secure exhaustion and when the process is sutliciently complete the chemical production of gases may be discontinued by the suppression of the exciting means.

in companion applications namely, Serial Number 265.503, filed June 16th, 1905, Serial Number 1903M. filed January 23rd,

: ita -l and in applicanfis- Patents $06,833 issued December Jlth, 1905, and 845,670

. sued l el'iruary 26th, 1907 are found claims: on subjectmatter related to that ot" the claims of the present case.

I claim as my invention 1. In an apparatus for exhausting a heri inetically sealed chamber through the action and 7 i l i i l i l of vaporization and expulsion of a volatilizable liquid, auxiliary expelling means said means consisting. of an additional more easily volatilizable liquid introduced in the chamber prior to exhaustion.

2. A method of exhausting a hermetically sealed vessel containing a volatilizable liquid which consists in adding a second more volatilizable liquid supplying heat to the oiit deleterious gases and expelling the vapors of the second liquid by vaporizing a portion of the first liquid and sealing the container during the expulsion of the vapors from the first named liquid. p

Signed at New York. in the countyof New York. and State of New York. this 11th day of January. D. 190

' PER CY H. THOMAS. Witnesses lVM. H. GAPEL, Gnonei: H. S'rocinmmon. 

